Wondering what an industry standard is for estimating busy hour concurrent call maximums for a large organisation?
Is there a generally accepted standard ratio for number of users to maximum number of concurrent calls?
E.g. If you have an office with 1000 users (and you do not know existing volumes of calls from the internal PBX cause they don't want to tell you ) and you are going to migrate them to voip should you base a maximum concurrent call estimation using a ratio of 20% of users on a call at once ... should that % be lower or higher??
If someone could point me to some good documentation on the subject it would be greatly appreciated!!